The present invention relates to improvements in fluid-propelled apparatus for cleaning the internal surfaces of tubular bodies, such as pipes, conduits or like hollow structures which serve to convey or confine gaseous, liquid or flowable solid substances in industrial plants, residential areas or elsewhere. More particularly, the invention relates to apparatus for removing incrustations or other impurities or obstructions which adhere to the internal surfaces of hollow tubular bodies (hereinafter called conduits) by means of one or more cutting implements which are urged into engagement with the internal surface of the conduit.
It is already known to provide a composite (multi-piece) conduit- or pipe-cleaning apparatus with a device which propels the housing of the apparatus forwardly. The propelling device is mounted behind several cutting implements which are articulately connected to each other as well as to the propelling device. A drawback of such apparatus is that the articulately interconnected parts are likely to lie askew and to cause the apparatus to jam in the interior of a conduit. In many instances, presently known cleaning apparatus employ devices which cause the liquid behind the housing of the apparatus to apply to the housing blows and to thus promote partial or complete removal of incrustations or other impediments in the interior of the conduit. The impulses which are applied by the liquid are relatively weak because substantial amounts of pressurized liquid which fills the conduit behind the housing of the apparatus are permitted to penetrate into the front or downstream portion of the conduit. In other words, the entire kinetic energy of pressurized liquid (normally water) cannot be utilized to promote the removal of obstructions by the cutting implements of the apparatus.